Varroa sampling

This table contains data on Varroa infestation levels (the number of varroa mites found in the sampling event) measured in individual hives on a given apiary at a given time with a given quality standard. Varroa samples were collected from citizen and mined data using 3 standard method sources between the years 2012-2020. This data contains 11124 varroa sampling events. Roughly 21% of these events record zero mites present. The highest number of mites present in a single sampling event is 5016. Sampling events are collected from 04/02/12 to 11/11/20, and last on average 7.2 days each (range: 1.0-23.8 days). Roughly 75% of Varroa Sampling events occur between 3 and 9 days.

Data on mite infestation levels were collected from 3 sources by a standard method - natural mite falls - from 2012 to 2020, mainly in the spring, early summer, and late summer. Data were collected from 3 different sources of differing quality. Data from the highest quality, described as quality_control=2, was examined with the BeeVS diagnostic system (Apisfero, Turin, Italy), which consists of a high-resolution scanner to take a picture of the samples (sticky boards placed under the brood nest of colonies) and cloud-based software used to count the number of mites on the sticky boards. Data from the intermediate source is described as quality_control=1 and were examined manually by a trained group. Data from the poorest quality source is described as quality_control=0 and were examined manually by untrained individuals according to a classification scheme. Data was entered via a web terminal by whomever analyzed the sample. The software vetted the data for plausibility (rejection of values that exceed 100 mites/day) and completeness (rejection of values that did not fall between a 3 day and 21-day measuring interval). Data exceeding these limits, which can be found in the data set, has been imported from external resources and has been approved by the supervisor. The data collected by untrained individuals were checked by the supervisor for plausibility.

From 2012 to 2016 the project was only implemented in the Austrian province of Styria, where approximately 3500 beekeepers supervised 53000 to 56000 honeybee colonies. In 2017 the crowdsourcing initiative was extended to all nine Austrian provinces, consisting of 28032 to 30237 beekeepers and 329402 to 390607 honeybee colonies in their care.

The total number of samples collected is 11124. 4033 (36%) were medium quality samples (QC=1) and 3267 (29%) were high quality samples (QC=2).

The varroa survey dataset includes 99 users (beekeepers), 242 bee yards (apiaries), and 2,116 hives from the nine Austrian provinces for a total of 11124 records pertaining to varroa infestation.